1.Purchase approximately 10% more for overlapping and to provide the proper air gap between the purlins 
2.Cover the metal roof purlins with double-sided adhesive tape. Unroll the foil wrap insulation and attach it to the first purlin. 
3.Secure the bubble foil to the framing members with furring strips. Use a drill equipped with a screwdriver bit to drive the screws into the framing members.
4.Cover the seams of the bubble insulation with foil tape.